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- Опубликовано: 26 июн 2024
- The RF envelope of a single sideband (SSB) signal is compared to an Amplitude Modulated (AM) signal. RF power measurement is defined and illustrated, including Peak Envelope Power (PEP) and Average Power. The RF output power considerations for both SSB and AM signals are presented and demonstrated. Notes from this video are found here:
www.qsl.net/w2aew/youtube/Peak... 
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Alan, just want to thank you for the years of high quality content. I started watching when I was 12 or 13... Now I’m nearly done my degree in EE, and your videos have certainly been a part of keeping me inspired to follow this path. Keep up the good work!
Thoroughly enjoyed this! I think this video should be seen by every ham in training.
What a wonderful job you do explaining this topic. You drawings and notes are excellent!! Thank you.
I’ve been subscribed to your channel for about a year, and I look forward to very new video you release. I also follow a few pages that you follow such as The Radio Shops page and TRX Workbench. I’ve been licensed since 1970 and have remained somewhat radio active throughout that time. Your videos have taught me some troubleshooting tricks and techniques that have resulted in getting me into a restoration mode. In the past when I attended a hamfest I’d avoid radios and test equipment that were in a visible state of disrepair. Now, I look for them, so I can restore them and give new life to an old faithful piece equipment. 90% of the repair process is usually replacing failed capacitors. Just wanted to say thanks for all your hard work!
Thanks for the very clear descriptions!
While studying my ham radio exam I got confused about these concepts. Your video brought me clarification. Great! Thank you !
This person has amazing teaching quality. I worked hard to understand smith chart from class lecture. But Alan's video help me alot.
Yessir i agree
I just stumbled onto your feed via a google search, and I have to say that at least on this episode you do an excellent job of presenting. This is a distinct skill beyond comprehension of the subject matter (which you obviously also have). Your clear, and most importantly succinct, presentation of this stuff is top notch. Looking forward to seeing what else you've done on your channel.
I hope you enjoy my 300+ other videos as much as this one.
This is one of the best videos I've seen on this subject.
Absolutely superb explanation, as always. Thank you Alan for enlightening some aspects I was missing before I watched your video
To every viewer of this video (i assume many are students like me), please remember to exclude w2aew from your ad-block list. If you want high quality content such as this, support and give motives to this guy
What about disabling it completely so YT stays free ...?
So glad to see a new video from you. Happy new year!
Hi Alan, what a wonderfully factual, visual and practical video for all (experienced and the not-so-experienced!!) to use to understand a topic that is not too often discussed. A pleasure and so easy to watch as per usual; well done! Brian EI8EJB
Every ham can learn something from this video. Many thanks and 73.
As a new ham in VK land with a F licence, thanks for your video, when I can see the process , even though I read the literature, a visualisation helps a lot in seeing it set up as you talk through it.
Thank you for explaining. Most appreciated. I have been studying your tutorials and building your circuits to help me better understand. I'm having so much fun since I took up amateur radio. Thanks for your precious time and expertise.
Absolute quality video
More please! Things like discerning between good and bad modulation envelopes. What makes them bad,what makes them good. I feel that I don’t know exactly where I should be looking. For example, I here the phrase going into compression. Some people will be pointing to the peaks and some,the troughs. Should I be focusing on the very outer edges? Or the very center where the shaded areas are coming together. I hope my confusion isn’t rubbing off on anyone. If you already have more video on this, I’ll find it and you can disregard my question. You’ve definitely made things more clear. Thank you for sharing your knowledge.
Excellent explanation, well explained, thank you.
Best regards,Carl .
So many people think their rigs are only doing like 30 or 40 watts. The old Kenwood hybrids were very conservative with their PEP which is why they sound so good on the air. More people need to see this. 73 from Andrew VK2XXL
Excellent video Allen, as you always do. This video answers that big question as to whether the transceiver is putting out proper power levels, as many of us ask ourselves. I would like also to see the addition of the effects of the transmit ALC influence, particularly in regards to digital modes. I really enjoy your videos. Thanks, Bob K3TCT
Great video, I'm just studying for amateur extra class and on the section of PEP. Great explanation. 73, Tom
Hi Alan,
You have a knack of making these topics easy to understand with the visuals you use. :-) 73 WB3BJU
Excellent demonstration! I love the Icom 706 mkiig. 10 years of excellent service for me.
This was a brilliant video. More like this please!
Great video. It gives me a better understanding of SSB power, and be able to make proper adjustment(s) on my radio. I continuously use a oscilloscope on the Antenna output to see the envelope.
Great illustrations!
Excellent explanation and very nice examples. Thanks for the video. R
Thank you I learned something new today. And you reinforced what I was thinking.
Great video as always Alan. Many TNX for the Time you are spending for this Explanation,.
73s Tom
DB1IAT
Another perfect video I've been looking for. 👍👍👍👍❤❤
Good video .. I hope that many will pay attention.
It was a great video iam just learning this stuff i would like to learn how to peak and tune cb radios
100k congrats
Excellent video !
I recently picked up that fancy drawing tablet tech you're using in this video. Took some notes with it on some of your lesson videos earlier too!
Thanks Alan. Nice lesson as usual!
Just discovered your channel by chance, it's brilliant. Smith charts are awesome. Thank you for all the hard work. GM4GLG
I appreciate how you explained PEP on this video. Thaks
Very good explanation, thanks for share!!
As usual, a very good video. I really enjoy watching your videos. They help me understand a lot of stuff. Keep it up! 73 de DL6PT
I like that PTT to control keying and SG input. Simple yet elegant. Need to build one myself. Also, I always relearn something old. Your tidbits add chlorine to my old knowledge pool, which over time has become tainted with algae and needs cleaning out. Thanks!
thank you. I now feel better about how my radio is performing lol
Nice demo!
Fantastic video. Give us more!!!
Nice explanation and demo, as always.
Great video
Very nicely done!
I love your diagrams BTW. The ones in this video were especially good but I also mean in general.
Beautiful explanation
Thanks for the education! Great video as always.
Very good video thanks for sharing the knowledge.
excellent content 73 🎉
Takes me back to broadcast engineering training when I was training to work on the maintenance of broadcast transmitters which ranged from a couple of watts up to 500kw in all broadcast bands.
Transmitters tend to have a duty cycle which says for how long a AM transmitter can run 100% modulation before the power amplifier starts to overheat and shutdown, but as the modulation was fairly low and normally music and voice the transmitters seldom if ever go near the duty cycle rating.
Many amateur radio transceivers have a duty cycle figure which for a quality transciever will be shown in the manual or the specification.
I learned a lot there watch this video. I appreciate the video so much I wish you lived near me!
Great video as usual Alan. The single tone method using my frequency counter you taught me is how I tune all my SSB boat anchors. I have told many other hams about you and many use that method. Great stuff.
I have a Drake W4 watt meter in my shack. I would like to learn more about adding the peak responding circuit you mentioned.
73s
KF6HF
You might take a look at the PDC-1 - it might be adaptable to the W4:
www.hi-rescom.com/html/pdc-1.html
One of the reviewers on eham put one in his W4:
www.eham.net/reviews/detail/999
Of course, the Drake W4 Wattmeter is not a low end part, but the conversion which Peter describes here ruclips.net/video/Mt0A1hQ_uR0/видео.html is also valid for this. In any case, I have rebuilt my W4 exactly the same way and it works flawlessly.
73 Bernd
Very good, presentation.
Very nice video. Those days i am building an ssb tranceiver and i realised that there arent any videos about that modulation.
Very very good video. Thank you. !!
this helped me understand my cb radio swr/power meter and why it was only showing an average rated reading of less than 10 watts while talking on ssb. it doesn't mean that the radio is not putting out it's full pep, which is reassuring.
Very Professional Sir
Great video! Thanks
Awesome channel 👍
I really liked this video, thank you for sharing! Are you using just a 10x probe in this example? I'm just curious about what's necessary for input protection. I'd also like to see your explanation of bessel functions in FM modulation, not sure if that is something you'd take the time to create as it certainly would take some effort but I think I speak for most of your viewers here on RUclips, you are an asset to the electronics and amateur radio communities and we are very grateful for your hard work in making these excellent videos!
Have you seen my video that discusses FM deviation measurements using Bessel Null?
ruclips.net/video/8IBOYoIV5m8/видео.html
...and yes, I was using a 10x probe. You'll have to check your probe's ratings to be sure of the safe operating area.
Good to see a ReMarkable tablet being used - I love mine though just can't write a neatly as you seem to be able to!
As always. great video :-)
The notes you see are usually the fourth or fifth iteration - or more!
clears a lot up, thanks
Useful video 👍
Wish the overmodulated splatter box idiots would learn from this, by far the best explanation of real power vs "bird watts " thanks!
Buenisimo el video bien educativo muy bien explicado y mas tratandose de radios lo felicito hasta me motivo para comprar un osiloscopio para envolverme en reparación de radios hf
Many thanks for your explanation. A lot of "spécialistes" in France try to let believe the owners that their TX need to be adjusted and I saw one who wrote he can increase the power by modulating more than 100% in AM mode.. with no distorsion aso. This one no more let ask pubicly about this kind of claims.. Thx again, sincerly yours
Very cool, checking for more like this. I got myself a Siglent SDS1202X-E 200 Mhz Digital Oscilloscope for Christmas, I'm already looking at some of the above signal on my IC-706MKIIG. I already had the Nano VNA H4 a year, and I'm making good use of it! 73 W7XLR
Excellent video Alan! This shows exactly why so many so-called techs horribly mess up CB radios in the attempt to make them put out more power. I’m a firm believer in using a monitor scope to set the modulation level of a transmitter on AM and SSB. Also, a lot of hams don’t really understand that much of the transmitted signal in an AM station comes from the modulator in the form of audio power.
A similar video regarding power measurements for FM and RTTY/ data modes would be good also.
FM and RTTY are both constant amplitude modes (both modulate the frequency, not the amplitude), so the RF envelope is constant.
Another great video, TNX fr the upload!
73 N8AUM
Alan, awesome pre-COVID video Sir. I want to run the two-tone test in one of my radios but I wonder what each tone should be set in each generator in my service monitor. I was thinking one tone at 500hz and the other at perhaps 1200hz. I use 1000hz when performing single tone (AM modulation adjustment). Thanks!
Thanks 4 Video !🆒📡📐📚📗
Hi Alan -- K4VU here. big fan (i binge watch your videos late at night). any chance you might be able to do a video on push-pull amp design and theory?
Very interesting !
Thank you!!
Is very Good video , 73
Very nice video :-)
Good explanation. Thank you.
Could you maybe do a video on the Weathstone Bridge regenerative receiver? As build by N1BYT?
I can’t seems to grasp how this actually works. I’ve build it, it works. But I’m still a bit baffled about how.
Alan, thanks for another awesome video. I had fun replicating the demo in the shack and discovered some interesting two-tone envelopes on one of my rigs. Do you have a reference of how to diagnose distortion seen in the two-tone SSB envelope output? Thanks again. -Andy KB7ZUT
No additional references at this time. Make sure to adjust the tone amplitudes for equal modulated response.
Great video , well explained. Thanks. GI4GID Belfast Ireland
👍Thank you sir.
Very nice Job Alan, especially on the two tone explanation on SSB.
Q: Should we use 700/1900 Hz for the two tones? If not, what are the most common?
The actual tone frequencies isn’t terribly important. Just be sure to adjust them for equal modulated amplitude (crossing points in RF envelope should be very sharp).
Hi Alan, Always enjoy your well explained videos. Bob Allison, the test engineer for the ARRL came out with a book a few years back titled, "Amateur Radio Transceiver Performance Testing;" I suspect you have seen it. Some videos covering more detailed rx alignment and procedures would be great. 73, Glenn WA4AOS
I've got Bob's book. Good idea to produce some videos using these procedures.
This is useful for optical communications as well in some parts.
Enjoyed the video! Understandable, you said effective and it reminds me of the root mean squared of AC. effective value of AC.( .707 times the peak or 1.414 the rms) If the meter was quick enough to read it in real time it would be accurate. RF carrier is fast according to what frequency it's tuned to. The lower signal which modulates or rides on the carrier.... I imagine it has an effect on the carrier... like harmonics ( I play guitar so I know about harmonics)..... But both average out mathematically, (I'm sure there is a formula!!!) If it all was converted to DC with a rectifier it'd be double on the top reading on the scope right? Or eliminated to one half the signal on top. And if a L or pi filter, an inductor in series with one or two capacitors to ground, (a resonant filter tuned for that frequency) the carrier would be eliminated. Right? I've been watching you for a while. I enjoy your channel.
Very informative and a really good refresher, thanks for what you do. 73 Mel VE3OJN
Interesting how the IC-706 power output meter jumps around with AM (10:05) and two tone SSB (11:00) and isn't constant like the Bird meter. That can add to the frustration when you can't trust the meter. Not just the 706 of course.
Thanks Alan, nice explanation of what can be confusing for a lot of us! 73 - Dino KL0S
Very interesting
Great 👍🏻 🌷
Great video,, your a wealth of good rf technique. W5SLW
Excelente.
Hi Alan. Thanks again for another great video. I have just started reading the section on PEP and ERP in the new ARRL handbook so this will undoubtedly make things clearer. Gong to try and read through the whole book over the winter☺️. What would you recommend for a scope adaptor? I actually have a 706 Mk2G sitting on my bench that I am going to install in my Land Rover, mainly for VHF but will also try HF. I might try repeating some of your video. Thanks again.
I have a few videos on RF Samplers that you might want to review.
@@w2aew thanks. I will carry out a search.
Gordon Wedman - If you want to buy one, instead of build one, here’s one that I can recommend. I needed an extra one, for my field kit, and this one works very well. Building it is half of the fun, but when it comes to test equipment, buying a proven design is the best decision, unless you can test and verify the accuracy of your own build. www.ebay.com/itm/RF-Sampler-1-50-MHz-Modulation-monitor-See-your-signal-SSB-CW-AM-FM-Data/162200390778?hash=item25c3e58c7a:g:~msAAOSwZQxW2M8~
@@Willam_J Hi William and thanks for the recommendation. I have put that on my eBay watch list. Always good to know someone else has tried something and found it to work before buying. Cheers.
Any suggestions for an inline sub watt power meter? SWR would be nice but isn't required.
Great video. I would have been interested in seeing the watt meter responding to your voice in AM mode. K3OHU
Thanks for the lesson. Is the Bird meter a thermoelectric thermocouple type of movement as it seems to display a lagged response?
It is a diode detector type meter, but the meter movement has a fair amount of inertia and damping on it's own.
Greetings Alan, Thank you for your videos, electronics is always an interest to me and you do a great job of making it a comprehensible subject.
I got a question for you if you have time. On an Oscilloscope, when do we use AC coupling or DC coupling and what does it do and Mean?
Thank you in advance. 73. KD9JMQ.
I did a video on that. Excuse the video quality, it was done 7 years ago, before I had refined my video skills and had a HD camera:
ruclips.net/video/Hkq-fvb5-NI/видео.html
Another interesting video thank you, can I ask how do you connect your scope to the output of your transmitter, would this likely effect the SWR / impedance seen by the transceiver ? In one of your videos you spoke about not connecting the output of your transmitter directly into your scope, on this video I am guessing this is what you were doing as you were seeing 200v 100w. Many thanks.
I was definitely NOT connecting the RF output directly to the scope. If you look carefully at the image at the 7:00 mark, you can see what I'm doing. The transmitter is connected to the input of the Bird wattmeter. The output of the wattmeter goes into a Tee connector. One side of the Tee is connected to another piece of coax that runs down to my dummy load (under the bench, out of view). The other end of the Tee has an adapter that accepts the 10x oscilloscope probe, and the probe is connected to the scope. i describe this over the next minute or so in the video. At 7:50, I zoom in a little more and you can see the probe adapter more clearly.